Demolition firing device



6, 1955 P. L. GODCHAUX 11, ET AL 2,715,365

DEMOLITION FIRING DEVICE Filed May 9, 1947 2 Sheets-Sheet l P. L. GODCHAC. A. BORCHE United dtates DEMIDLETEGN FERENG DEVICE Paul Leon Godchaux1!, New Urleans, La., and Charles A. Beecher, Silver Spring, Md.

Application May 9, 1947, Serial No. 747,117

7 Claims. (CE. 102-- 7) (Granted under Title 35, U. S. ode (1952), see.266) This invention relates to a demolition firing device adapted foruse either on land or water, and more particularly to a device forfiring in predetermined time delayed relation a main demolition chargeand a plurality of additional demolition charges detachably securedthereto.

The present invention provides a new and improved demolition firingdevice in which means are employed for quickly and detachably securingan explosive trunk line thereto, the trunk line having a plurality ofadditional explosive charges operatively connected thereto and adaptedto be fired thereby in predetermined time delayed relation with respectto the firing of the delay element within the demolition device.

More particularly the present invention relates to a demolition firingdevice adapted to fire a plurality .of demolition charges and therebycause wholesale destruction of enemy shore or underwater obstacles such,for

example, as barbwire entanglements and .underwater barriers and thelike. The device of the present invention is adapted to fire a length ofPrimacord and a plurality of explosive charges connected thereto, theexplosive force therefrom being adapted to destroy underwater obstaclesthereby permitting landing operations to be executed efficiently andquickly, as time is most essential when such landing operations are inprogress. The device is adapted to be quickly attached to and fire alength of Primacord and concurrently therewith a plurality of explosivecharges operatively connected thereto thereby to clear a'beach ofbarriers and permit landing boats and troops with their equipment tomake a safe landing there on. The device in connection with theaforesaid demolition charges may also be employed for destroying secretand confidential military equipment used by our armed forces in theevent that sudden seizure thereof by the enemy appears probable. Thedevice of the present invention, therefore, .is adapted to fire a lengthof Primacord including a plurality of spaced additional Primacordssecured thereto when a predetermined period of time has elapsed afterthe device has been set in operation, thereby to demolish water or landbarriers.

One of the objects of the present invention is the provision of ademolition firing device in which means are employed for firing a lengthof Primacord connected to a plurality of explosive charges inpredetermined time delayed relation with respect to the initial firingof the firing device.

Another object of the invention is the provision of a new and improvedfiring device in which a plurality of demolition charges are adapted tobe quickly and detachably secured .thereto and fired thereby.

.Another object of the invention is the provision of a new andtimprovedfiring device adapted to fire an elongated explosive charge andconcurrently therewith a plurality of additional explosivechargesconnected thereto.

A still further object is to provide a new and improved demolitionfiring device which is economical to ,manu- 2,715,365 Patented Aug. 16,1955 ice facture, reliable in operation and which possesses thequalities of durability and safety during handling and transportation.

Still further objects, novel features and advantages of the inventionwill become apparent from the following description taken in connectionwith the accompanying drawings, wherein:

Fig. l is a view of the demolition firing device showing the manner inwhich the demolition charges are secured thereto;

Fig. 2 is an enlarged longitudinal sectional view of the demolitionfiring device of Fig. 1 showing the parts thereof in a safe or unarmedposition;

F ig. 3 is a view similar to Fig. 2 but showing the demolition firingdevice in the armed position in full lines and also showing the plungerin the firing position thereof in dashed lines; and

Fig. 4 is a sectional view taken on the line 44 .of Fig. 2.

Referring now to the drawings for a more complete understanding of theinvention, the demolition firing device disclosed thereon is generallyindicated by the reference character and comprises an elongated casing11 including a tubular insulating body 12 composed of any materialsuitable for the purpose such, for example, as plastic and havingthreaded engagement with a sleeve 13 adapted to slideably receive afiring mechanism generally indicated by the numeral 14. Secured to thetube 13 in any suitable manner such, for example, as by threading theparts together is an adapter 15, the adapter comprising a body 16, endwall 17 integrally formed thereon, and an internally threaded well '18adapted to have threaded engagement with one end portion of a member 19.

The member 19 comprises a head 21 having a reduced tubular sleeve 22integrally formed thereon and spaced a predetermined distance from theinner periphery of the body 12 thereby to provide an air spacetherebetween, the end portion thereof being secured to the adapter inthe aforesaid manner.

An exploder generally indicated by the reference character 23 andcomprising .a casing 24 is secured to the head 21 in ,any suitablemanner preferably by a nipple 25 secured to one end of the exploder andhaving threaded engagement with the internally threaded portion of thehead 21, the nipple being secured to the casing 24 of the exploder asbythreaded engagement therewith. As clearly shown on Figs. 2 and 3 thenipple is threaded into the casing 24 a predetermined amount thereby toprovide a chamber 26 within the casing, the chamber being dis- ,posedbetween one end portion of the nipple 25 and a relative thin Wall '27 onthe exploder. Arranged within the chamber and in abutting engagementwith one end portion of the nipple 25 and with the wall 27 is .anexplosive charge 28 such, for example, as a tetryl pellet. The

nipple 25 is provided with a centrally disposed bore 29 extendingtherethrough in which is arranged a sleeve 31 composed of any materialsuitable for the purpose. Disposed within the sleeve 31 is a detonatorhaving one end thereof in abutting engagement with the tetryl pellet 28,the other end thereof being in abutting engagement with an ignitercharge 32 arranged within one end of the sleeve '31 ,and adapted to firethe detonator which, in turn, fires the tetryl pellet 28 inpredetermined time delayed relation with respect to the firing of adelay train 33 arranged within a bore 34 formed in the sleeve 22.

The delay train comprises a plurality of pellets 35 arranged in abuttingengagement with respect to each other andeomposedof any freeandcomparatively slow burning;powder suitable for;the purpose, the burningtime ,of the delay 'train being subjected to variations such, for

example, as from 30 to seconds depending upon the length of the delayassembly disposed therein. As shown on Figs. 2 and 3 the pellets of thedelay train are arranged in abutting relation with respect to each otherand the end pellets thereof are respectively arranged in engagement withan igniter charge 36 disposed in one end of the sleeve 22 and one end ofthe igniter charge 32 disposed in one end of the sleeve 31. Thus acontinuous combustible train is provided from a percussion cap or primer37 arranged within the reduced portion of the well 18 to the detonator30.

As best shown on Figs. 2 and 3 the casing 24 of the exploder hasarranged therein a slot adapted to receive an explosive Primacord 38 ofany desired length and detachably secured in the slot adjacent thepellet 28. The

walls defining the restricted portion 37' of the slot are substantiallyparallel with respect to each other and terminate in a substantiallycircular portion 39. By this arrangement the Primacord" is compressed ordistorted as the cord is inserted into the restricted portion 37 of theslot, it being understood, that the cord is of greater diameter than thewidth of the restricted portion of the slot. Thus when the Primacord hasbeen forced through the restricted portion of the slot and enters thecircular portion thereof it seats therein. When this occurs thePrimacord will assume its original shape Figs. 2 and 3 thereby toprevent the cord from being readily withdrawn from the slot and alsodisposing the Primacord in the most advantageous position with respectto the pellet 28 such that the full force of the explosion as the pellet28 is fired will be concentrated on the Primacord thus causingdetonation thereof.

Secured to the Primacord 38 in any suitable manner such, for example, asshown on Fig. 1 of the drawings is a plurality of spaced Primacord 41having respectively arranged on the free ends thereof a container 42 inwhich is disposed a quantity of explosive material 43, it beingunderstood, however, that as the Primacord 38 is fired by the pellet 28,the spaced cords 41 and explosive material within the containers arefired concurrently therewith, the force of the explosion therefrom beingsufiicient to destroy the defense barrier. While the invention has beendescribed as employing a container secured to an end of each Primacordand having a quantity of explosive material therein, it will beunderstood, however, that any suitable explosive may be used such, forexample, as plastic explosive, the plastic explosive being adapted to bemounted on the free ends of the cords, if desired.

The firing mechanism 14 comprises a plug 44 slideably arranged within awell 45 disposed in one end of the sleeve 13 and extending apredetermined distance therebeyond, Figs. 2 and 3. Integrally formed onthe plug 44 is a shank 46 extending a predetermined distance into areduced bore 47 arranged in the sleeve 13 and in communication with thewell 45, the shank having a lug 48 formed thereon on which is disposed acam surface 49, the purpose of which will be more fully describedhereinafter.

A sealing gasket 51 composed of any material suitable for the purposesuch, for example, as rubber or the like is arranged within the well 45and disposed between one end portion of the plug 44 and a shoulder 52 onthe sleeve 13 thus providing a moisture proof seal therebetween wherebydeterioration of the pyrotechnic materials contained within thedemolition firing device is prevented. The gasket 51 is provided with acentrally disposed opening 53 through which the shank 46 extends.

A plunger 54 is slideably arranged within the bore 47 and releasablyconnected to the shank 46 and comprises a body 55 having a fiutedstriker 56 formed on one end thereof, the other end being provided witha lug 57 adapted to seat in a recess or cutaway portion 58 arranged inthe shank 46. As shown on Figs. 2 and 3 the plunger 54 is provided witha recess or cutaway portion 59 thereby to provide a seat for the lug 48.Lug 57 has formed thereon a cam surface 61 adapted to coact with thecomplementary cam surface 49 on the lug 48 thereby to release theplunger from interlocking engagement with the shank 46 when the shankhas been moved outwardly a predetermined amount. It will be understood,however, that when the plunger 54 has been moved outwardly to theposition shown in full lines on Fig. 3 in response to a sudden pull onthe pull ring 62 secured to the plug 44, by the operator, the shankthereon is disengaged from the plunger. When this occurs the plunger isfree to move inwardly to a firing position in response to the pressureapplied thereto by a spring 63 arranged within an enlarged bore 64 inthe tube 13 and surrounding the plunger, the respective ends of thespring being in abutting engagement with the striker 56 on the plungerand a shoulder 65 formed on the tube 13 at the juncture of the wallsdefining the bores 47 and 64.

lt will be apparent from the foregoing description, that the cam surface49 on the lug 48 is adapted to coact with the complementary cam surface61 on the lug 57 in such a manner as to permit release of the plunger 54from the shank 46 when the plunger has been moved to an armed position,Fig. 3. The release of the plunger is efiected in response to thepressure applied thereto by the spring 63, in conjunction with the camaction between the cam surfaces 49 and 61 as the plunger is movedoutwardly sufiiciently to bring the lugs 48 and 57 beyond the shoulder65 and into the well 45. When this occurs the lugs 48 and 57 will becomedisengaged and release of the plunger is elfected.

As the plunger is released it is moved to a firing position shown indashed outline on Fig. 3 in response to the pressure exerted thereon bythe spring 63, the striker 56 being driven into engagement with thefiring pin 66 with suflicient force to drive the pin into firingengagement with the percussion cap 37 thereby to initiate firing of thetime delay train 33. The firing pin 66 is slideably arranged in a bore67 disposed within the wall 17 of the member 15 and maintained thereinby complementary shoulders 68 and 69 respectively formed on the firingpin and the wall 17. A reduced end portion 71 of the pin 66 extends aslight distance beyond the outer surface of the wall 17 in such a manneras to permit the striker 56 on the plunger to engage the portion 71thereon and move the pin a predetermined amount as the plunger is movedto the firing position by the spring.

As shown on Fig. 2 the device is maintained in a safe condition by a pin73 extending through a bore 74 arranged in the plug 44 and complementaryopenings 75 in the sleeve 13, thus sliding movement of the plug isprevented until the pin is withdrawn from the aforesaid bore andopenings.

It will be understood, however, that when the demolition charges aredesired to be fired, safety pin 73 is removed from engagement with theplug 44 and sleeve 13, Fig. 2, the ring 62 secured to the plug 44 willbe grasped by the operator and a direct outward pull applied thereto bythe operator whereupon sliding movement is imparted to the plug 44 andplunger 54, the spring 63 is additionally contracted between the striker56 and shoulder 65. After the plug 44 has been moved a predeterminedamount by the operator, the lug 48 on shank 46 will become disengagedfrom lug 57 on plunger 54 in response to the pressure exerted on theplunger by the spring 63 and the action between the cam surfaces on lugs48 and 57 thereby releasing the plunger from interlocking engagementwith the shank.

When the plunger has been released continued action of the spring 63will urge the plunger to a firing position as shown in dashed outline,Fig. 3 with the striker thereon in operative engagement with the firingpin 66, the force exerted on the firing pin by the spring beingsufiicient to fire the percussion cap 37 thus igniting the ignitercharge 36 arranged on one end of the time delay train 33 which in turnignites the delay train. After a predetermined period of time controlledby the delay train has elapsed, the igniter charge arranged in one endof the sleeve 31 will be ignited thus initiating firing of the detonator30. As the detonator is fired the force of the explosion therefrom issufficient to fire the tetryl pellet 28, and concurrently therewith, andinitiated thereby, the Primacord 38 is fired, which in turn fires thePrimacords 41 and explosive charges 43, the force of the explosion ofthe charges and the Primacords being sufiicient to destroy underwater orfield barriers, as the case may be.

It will be understood, that the demolition firing device is preferablyemployed for firing a plurality of demolition charges placed under waterby a crew of skilled swimmers thereby to destroy underwater barrierssufficiently to permit landing boats and the like to be beached quicklyand with negligible damage thereto, and in which the delay train afterignition thereof burns sufiiciently slow to permit the swimmer to bewell out of range of the explosion when the demolition charges arefired.

While the device has been described in particularity with reference to aplurality of demolition charges adapted to be fired thereby in timedelayed relation for destroying underwater barriers and the like, itwill be understood that, if desired, the device may be used inconnection with destroying secret equipment, field equipbodiment of thedevice is illustrated and described, it is to be understood that changesin the details of construction and in the combination and arrangement ofparts may be resorted to which fall Within the scope of the invention asclaimed.

The invention disclosed and claimed herein may be manufactured and usedby or for the Government of the United States of America forgovernmental purposes without the payment of any royalties thereon ortherefor.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. A demolition firing device comprising an elongated casing, a headsecured to one end of said casing and having a slot formed therein, saidslot comprising a restricted portion and a circular portion forreceiving and quickly locking an explosive cord of greater diameter thanthe width of said restricted portion to said head as the cord is forcedthrough the restricted portion into said circular portion, a slowburning time delay element arranged within said casing, a releasablefiring means slideably arranged within the casing and adapted to bemoved a predetermined amount to an armed position, means releasablysecured to said firing means for actuating the firing means to saidarmed position, a pair of complementary inclined cam surfaces arrangedon the firing means and the actuating means respectively for releasingsaid firing means as the firing means is moved to said armed position,resilient means operatively engaging said firing means for urging thefiring means from said armed position to a firing position as the firingmeans is released thereby to fire said time delay element, a detonatorfired by the time delay element in predetermined time delayed relationwith respect to the firing of the delay element, an explosive chargearranged within said head in abutting engagement with said detonator andfired thereby, and a wall on said head composed of relatively thinmaterial in abutting engagement with said explosive charge and saidexplosive cord and efiected by the force of the explosion as theexplosive charge is fired for applying sufficient shock to said cord tocause detonation thereof.

2. A demolition firing device comprising an elongated casing, a headsecured to one end of said casing and having a slot formed therein, saidslot comprising a restricted portion and a circular portion forreceiving and quickly locking an explosive cord of greater diameter thanthe width 'of said restricted portion to said head as the cord is forcedthrough said restricted portion into said circular portion, a detonatorarranged within said casing, a slow burning time delay element abuttingthe detonator, a releasable firing plunger slideably arranged withinsaid casing and adapted to be moved a predetermined amount to an armedposition, means releasably secured to said firing plunger for actuatingthe firing plunger to said armed position, means on said firing plungerand adapted to coact with complementary means on the actuating means forreleasing said firing plunger as the plunger is moved to said armedposition, a spring operatively engaging said firing plunger for urgingthe firing plunger from said armed position to a firing position as thefiring plunger is released thereby to fire the time delay element andexplode the detonator in predetermined time delayed relation withrespect to the release of the firing plunger, explosive means arrangedwithin said head in abutting engagement with said detonator and fired bythe detonator, and a wall on said head composed of relatively thinmaterial in abutting engagement with said explosive means and saidexplosive cord and effected by the force of the explosion as theexplosive means is fired for applying sufiicient shock to said cord tocause detonation thereof.

3. A demolition firing device comprising an elongated casing, a headsecured to one end of said casing and having a slot formed therein, saidslot comprising a restricted portion and a circular portion forreceiving and quickly locking a percussion type explosive cord ofgreater diameter than the width of said restricted portion to said headas the cord is forced through the restricted portion into said circularportion, a percussion cap arranged within said casing, releasable firingmeans arranged within said casing and adapted to be moved slideably toan armed position, means releasably connected to said firing means foractuating the firing means to said armed position, means on saidactuating means for releasing said firing means as the firing means ismoved to the armed position, -a resilient member surrounding said firingmeans for urging thefiring means from said armed position to a firingposition as the firing means is released thereby to fire said percussioncap, an explosive charge arranged within said head, a detonator forfiring the explosive charge, a wall on said head composed of relativelythin material in abutting engagement with said explosive charge and saidexplosive cord and effected by the force of the explosion as theexplosive charge is fired for applying suflicient shock to said cord tocause detonation thereof, and means fired by said percussion cap forexploding the detonator in time delayed relation with respect to thefiring of said percussion cap.

4. A demolition firing device comprising an elongated casing, a headsecured to one end of said casing and having a slot formed therein, saidslot comprising a restricted portion and a circular portion forreceiving and quickly locking a percussion type demolition charge ofgreater diameter than the width of said restricted portion to said headas the cord is forced through said restricted portion into said circularportion, a time delay element arranged within said casing and adapted toburn for a predetermined period of time when ignited, means including apercussion cap for igniting said time delay element, firing meansarranged within said casing and adapted to be moved slideably to anarmed position,

means releasably connected to said firing means for actuating the firingmeans to said armed position and adapted to release the firing meanswhen moved to the armed position, a spring operatively engaging saidfiring means and said casing for urging the firing means from said armedposition to a firing position as the firing means is released thereby tofire said percussion cap, means on said actuating means for releasingsaid firing means, an explosive charge arranged within said head, adetonator fired by said time delay element for initiating the explosionof said explosive charge, and a wall on said head composed of relativelythin material in abutting engagement with said explosive charge and saiddemolition charge and eifected by the force of said explosion forapplying sufiicient shock to said cord to cause detonation thereof.

5. A demolition firing device comprising a casing, a head secured to oneend of said casing and having a slot formed therein, said slotcomprising a restricted portion and a circular portion for receiving andquickly locking an explosive cord of greater diameter than the Width ofsaid restricted portion to said head, means on said casing fordetachably securing said cord, a releasable firing plunger slideablyarranged within said casing and adapted to be moved a predeterminedamount to an armed position, means detachably secured to said firingplunger for actuating the plunger to said armed position, means on saidactuating means and including a gasket for hermetically sealing thecasing until the actuating means is moved said predetermined amount, aspring surrounding the plunger for urging the plunger from said armedposition to a firing position when the actuating means is detachedtherefrom, an explosive charge, means fired by the plunger forinitiating the explosion of said explosive charge, and a wall on saidhead composed of relatively thin material in abutting engagement withsaid explosive charge and said explosive cord and eflected by the forceof said explosive for applying sufficient shock to said cord to causedetonation thereof.

6. A demolition firing device comprising an, elongated casing, a headsecured to one end of said casing and having a slot formed therein, saidslot comprising a restricted portion and a circular portion forreceiving and quickly locking a demolition cord of greater diameter thanthe width of said restricted portion to said head as the cord is forcedthrough the restricted portion into said circular portion, an explosivecharge disposed within said head, a wall on the head composed ofrelatively thin material in abutting engagement with said explosivecharge and the demolition cord and effected by the force of theexplosion as the explosive charge is fired for applying suificient shockto said cord to cause detonation thereof, a detonator arranged withinthe head in abutting engagement with said explosive charge for firingsaid charge, a delay element arranged within the casing for firing saiddetonator when a predetermined period of time has elapsed, and meansincluding a percussion cap arranged within the casing for igniting saiddelay element.

7. A demolition firing device comprising an elongated casing, a headsecured to one end of the casing and having a slot formed therein forreceiving and quickly locking a percussion type demolition chargetherein, said head having a wall composed of relatively thin materialbordering on one side of said slot in engagement with said demolitioncharge and adapted to be driven suddenly and forcibly into firingengagement with said charge, said head having a mass bordering on theother side of said slot in engagement with the demolition charge forpreventing movement and etfecting the blow of said thin wall against thedemolition charge as the thin wall is driven into said firing engagementtherewith, a detonator arranged within said casing, an explosive chargedisposed within said head in abutting engagement with the thin wall andfired by said detonator for driving the wall into firing engagement withsaid demolition charge, a delay element arranged within the casing forfiring said detonator when a predetermined period of time has elapsed,and means including a percussion cap arranged within the casing forigniting said delay element.

References Cited in the file of this patent UNITED STATES PATENTS 44,630Hughes Oct. 11, 1864 1,683,940 Wiley Sept. 11, 1928 1,887,122 Duffy Nov.8, 1932 2,380,312 Johnson July 10, 1945 2,382,879 Imber Aug. 14, 1945FOREIGN PATENTS 347,180 Germany Jan. 16, 1922

